Grain not provided for TimeInterval

[joffreyvillard]

Hey,
Sorry for the bunch of issues filled today :/

When the utterance is a time interval , e.g. "between 2017 and 2018", then no grain is provided:

{
      "entity": "snips/datetime",
      "range": {
        "end": 21,
        "start": 0
      },
      "rawValue": "between 2017 and 2018",
      "slotName": "date-time",
      "value": {
        "from": "2017-01-01 00:00:00 +01:00",
        "kind": "TimeInterval",
        "to": "2019-01-01 00:00:00 +01:00"
      }
    }

This sentence "between 2017 and 2018" hence results in the same entity as "between Jan 1st, 2017 and Dec 31st, 2018". The timeframe expected by the user may or may not be the same in both cases, and the second form may indicate that the user expects some more details, being herself more accurate in her question.

I don't know of course how difficult it would be to add this, but FYI Duckling behaves this way: https://duckling.wit.ai/

Joffrey